C3 and retinal degeneration: Additionally, given the complexity and the degree of crosstalk between various immune pathways, other transcription factors (TFs), such as Hmox1, NFkB, and NFE2L2, might also interact with the C3a-C3ar1 pathway and be involved in retinal degeneration (Karlen et al., 2020; Potilinski et al., 2021).